Too Much of a Good Thing: How Ectopic DNA Replication Affects Bacterial Replication Dynamics
| Autor: | Christian J. Rudolph, Ole Skovgaard, Aisha H. Syeda, Juachi U. Dimude |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Microbiology (medical)
replication Cell division lcsh:QR1-502 bacterial replication dynamics Review Biology Genome Microbiology lcsh:Microbiology 03 medical and health sciences recG gene Transcription (biology) Gene duplication Gene termination of DNA replication ectopic replication origins 030304 developmental biology 0303 health sciences 030306 microbiology Circular bacterial chromosome DNA replication Chromosome Evolutionary biology transcription 3′ exonuclease |
| Zdroj: | Frontiers in Microbiology Frontiers in Microbiology, Vol 11 (2020) |
| ISSN: | 1664-302X |
| Popis: | Copyright © 2020 Syeda, Dimude, Skovgaard and Rudolph. Each cell division requires the complete and accurate duplication of the entire genome. In bacteria, the duplication process of the often-circular chromosomes is initiated at a single origin per chromosome, resulting in two replication forks that traverse the chromosome in opposite directions. DNA synthesis is completed once the two forks fuse in a region diametrically opposite the origin. In some bacteria, such as Escherichia coli, the region where forks fuse forms a specialized termination area. Polar replication fork pause sites flanking this area can pause the progression of replication forks, thereby allowing forks to enter but not to leave. Transcription of all required genes has to take place simultaneously with genome duplication. As both of these genome trafficking processes share the same template, conflicts are unavoidable. In this review, we focus on recent attempts to add additional origins into various ectopic chromosomal locations of the E. coli chromosome. As ectopic origins disturb the native replichore arrangements, the problems resulting from such perturbations can give important insights into how genome trafficking processes are coordinated and the problems that arise if this coordination is disturbed. The data from these studies highlight that head-on replication–transcription conflicts are indeed highly problematic and multiple repair pathways are required to restart replication forks arrested at obstacles. In addition, the existing data also demonstrate that the replication fork trap in E. coli imposes significant constraints to genome duplication if ectopic origins are active. We describe the current models of how replication fork fusion events can cause serious problems for genome duplication, as well as models of how such problems might be alleviated both by a number of repair pathways as well as the replication fork trap system. Considering the problems associated both with head-on replication- transcription conflicts as well as head-on replication fork fusion events might provide clues of how these genome trafficking issues have contributed to shape the distinct architecture of bacterial chromosomes. Biotechnology and Biological Sciences Research Council Biotechnology and Biological Sciences Research Council, research grants BB/K015729/1 and BB/N014995/1. |
| Databáze: | OpenAIRE |
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